Revolution in Winter Tires

Tires tested:
Bridgestone Blizzak REVO 1
Bridgestone Blizzak WS-50
Dunlop Graspic DS-2
Michelin X-Ice
 

Vehicles used:
2006 BMW 325i E90

Ever since studded winter tires were banned in Japan & Bridgestone introduced Blizzak Studless Winter tires to help drivers get a better grip in the slipperiest winter road conditions they would face, many tire manufacturers have evolved their method of enhancing packed snow & ice traction. The traditional method of inserting road-damaging metal studs has given way to new technologies that combine unique tread compounds molded into sophisticated tread designs. It's turned out to be a win-win situation, because in addition to increased winter driving comfort, control & convenience, these new winter tire technologies have also reduced road repair costs.

Drivers now have several choices when it comes to selecting Studless Winter tires to match their driving conditions. Bridgestone continues to offer the popular Blizzak WS-50 "snow & ice" tire in addition to their new Blizzak REVO 1 "ice & snow" tire. While the distinction between the two is subtle, Blizzak WS-50 tires have been praised for their blend of snow & ice traction, while the new Blizzak REVO 1 tires are designed to further enhance traction on ice & in slush.

To find out how capable the Blizzak REVO 1 is, The Tire Rack team conducted a Real World Road Ride & Performance Ice Rink Drive to compare the Blizzak REVO 1 with several other popular Studless Winter tires, the Bridgestone Blizzak WS-50, Dunlop Graspic DS-2 & Michelin X-Ice. While the Blizzak WS-50 has been a traction leader in the Studless Winter category, the Graspic DS-2 offers Dunlop's best "ice-n-snow" traction at an attractive price, & Michelin's X-Ice combines ice & snow traction with enhanced cornering on wet & dry roads.

Our evaluation used 2006 BMW 325i automatic transmission-equipped sedans, fitted with new, full tread depth 205/55R16-sized tires mounted on 16x7.5" wheels.

What We Learned on the Road

Our 5.6-mile Real World Road Ride loop of public expressway, state highway & county roads near our South Bend headquarters provides a great variety of everyday road conditions with a mix of city & highway speeds, smooth & coarse concrete, as well as new & patched asphalt road surfaces. This course allows our team to experience the everyday cornering, ride quality & noise comfort of the products we drive on, just as you would during your drive to work.

Recognizing that the features that increase a Studless Winter tire's snow & ice traction (aggressive tread design, soft tread compound & deep original tread depth) also reduce their dry & wet road responsiveness, we "recalibrated" our cornering expectations & drove the tires accordingly. We found that by simply initiating steering input a little earlier & gradually turning the steering wheel a little farther than with all-season tires, we were able to place the car where we wanted & easily maintain our Real World Road Ride's normal speeds. Of the four Studless Winter tires tested, the Michelin X-Ice was considered the most responsive, followed by the Blizzak REVO 1, Blizzak WS-50 & Graspic DS-2.

The Blizzak REVO 1 smoothed out road imperfections to provide the best ride quality of the group, followed by the Blizzak WS-50, Graspic DS-2 & the X-Ice.

While all of the tires were a little louder than typical all-season tires when it came to generating noise across the variety of road surfaces in our test loop, none of them produced noise levels or noise qualities that were considered to be objectionable. Of the four winter tires the Blizzak WS-50 was considered quietest, followed by the Blizzak REVO 1, X-Ice & Graspic DS-2.

What We Learned on the Ice

In place of our normal test track drive, our team went to a local ice rink to experience these tires' ice traction & cornering. While it was 85ıı Fahrenheit outside, the ice rink provides the perfect conditions for getting the feel of ice traction & cornering in a controlled environment because the ice is as cold & slick as polished intersections will be in the middle of winter.

We use two tests that help eliminate the effects of the driver's reaction time, & reduce the possibility of driver error affecting the outcome of the tire's ratings. First, each car was lined up with its rear wheels on the goal line. We recorded the time it took for the car to cover the final 60 feet to the center of the rink as the car accelerated as fast as its traction control would allow.

During the acceleration test, the Blizzak REVO 1 tires proved Bridgestone's claims were justified. They ran the fastest 60-foot times of the four tires & earned a traction index of 100, followed by the Blizzak WS-50 (94 traction index) & X-Ice (93 traction index), with the Graspic DS-2 (86 traction index) finishing behind the other three winter tires.

However, when considering these acceleration results, it's also important to remember that all of the Studless Winter tires outperformed a representative Standard Touring All-Season tire by a considerable margin. The Standard Touring All-Season tires in this test had an ice traction index of only 66.

Then we tested each tire's ability to corner on ice as the car negotiated a simulated 90-degree right hand street corner while maintaining a predetermined speed. With traffic cones set every 6 feet along a line representing the center of the road being turned onto, we could determine how tight an arc the tire's traction would allow the car to maintain.

During the cornering test, the Blizzak REVO 1 completed our 90-degree right hand street corner at the target speed without make contact with any cones, followed by the Blizzak WS-50 (0.03 cone average), X-Ice (0.10 cone average) & Graspic DS-2 (1.29 cone average). Since a lower number of cones hit indicates the ability to maintain a tighter corner, fewer is better. We tried to include the Standard Touring All-Season tires in our cornering test, but they were unable to accelerate fast enough to reach the target cornering speeds within the confines of the ice rink.